Typewriter having typelevers mounted on a rotating member



Dec. 6, 1966 E. F. KLEINSCHMIDT ETAL 3,289,805

TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEMBER 6 Sheets-Sheet Filed Nov. 2'7, 1984 INVENTORS EDWARD F. KLEINSCHMDT SQ'EWART E. KL-EINSCHWDT m 0% mm m2 m5 NE E oi m 1966 E. F. KLEINSCHMIDT ETAL 3,

TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEMBER Filed Nov. 2'7, 1964 6 Sheets-Sheet 2 INVENTORS EDWARD F. KLEINSEHMIDT STEWART E. KLEiNfaCl-(MIDT mgw 1966 E. F. KLEINSCHMIDK' ETAL 3,289,805

TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEMBER 6 Sheets-Sheet 5 Filed Nov. 27, 1964 INVENTORS EDWAFZD F. KLEIMSCHMIDT ig EWAET E. KLEWS'CHMIDT A WOR/VE Y9 1966 E. F. KLEINSCHMIDT ETAL 3,289,805

TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEMBER FiledNov. 27, 1964 6 Sheets-Sheet 4- I N V EN TORS EDWARD F. KLENSCHWDT SB'E EWART E. KLEINCHMDT A TTORNE Y5 1966 E. F. KLEINSCHMKDT ETAL 3,289,805

TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEMBER Filed NOV. 2'7, 1964 6 Sheets-Sheet ls'r CHARACTER 64ihCHARACTER I51) CHARACTER SELECTED SELECTED SELECTED 8: PRINTED BIPRNTED EIPFUNTED E-COINCIDE (UNLA EM'SELECTION M-PRINTING DELAYED SPACE PU EM-SPACING E-ELEGTRONIC EM-ELEGTROMECHANICAL M-MECHANICAL INVENTOR EDWARD F. KLEINSCHMIDT STEWART E. KLEINSC HMIDT ATTORNEYS Dec. 6, 1966 E. F. KLEINSCHMIDT ETAL 3,

TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEIIIBER Filed Nov. 27, 1964 6 Sheets-Sheet 6 I I I I I I I I l I I I I I I I I I I I I I I I AC. SOURCE ELECTRONIC CONTROLLER SELECTOR Ll-l 5 FE INVENTOR g g g EDWARD F7 KLEINSCHMIDT m o z STEWART E.I LE|NSCHMIDT 81 o J a: O :6 I- N ATTORNEY United States Patent Ofiice 3,289,805 Patented Dec. 6, 1966 3,239,805 TYPEWRITER HAVING TYPELEVERS MOUNTED ON A ROTATING MEMBER Edward F. Kleinsclnnidt, Evanston, and Stewart E. Kleinscln'nidt, Prospect'lleights, lll., assignors to SCM (lorporation, New York, N.Y., a corporation of New York Filed Nov. 27, 1964, Ser. No. 414,188 37 Claims. (Cl. 197-118) This invention relates to electrically operated and signal controlled typewriters of the kind readily adaptable for use in conjunction with telegraphic systems and more particularly to a typewriter employing a unique and continuously rotating type head, capable of use with a platen roll as found in conventional typewriters.

Standard typewheel designs commonly used are of a simple and convenient design for presenting type to a printing medium but most embody the common objectionable characteristic of having to be momentarily arrested during the instant of actual printing. This, of course, creates greater wear and strain on various mechanical parts of the machines and also puts a limitation on the number of characters that can be printed in a given time. On-the-fiy typewheel printers, which use an auxiliary hammer, are not compatible for use with a conventional typewriter platen roll.

Other previously proposed printers with continuously rotating typewheels have pivoting type pallets mounted in such a manner as to require very precise synchronization in order to print all of the characters in a straight line. The pallets are moved to and from the printing position and retained in a non-printing position by means of springs, magnets, cams, and other similar means which, when coupled to an electronic selecting system, must be held to close synchronization. Otherwise, type pallets arriving a bit early or late at the printing position will cause the characters to be printed slightly above or below the line or, in some instances, will cause the characters to be only half printed, giving the page a generally uneven appearance which could be difficult to read.

In this present invention, a unique, continuously rotating type pallet wheel, carrying a plurality of counterweighted type pallet levers, operates at a fixed rotational speed, e.g., 1800 revolutions per minute, and accomplishes printing at from 100-200 words per minute in a perfectly straight line. The counterweighted type pallet levers are carried in a latched position on the rotating type pallet wheel and at a specific point, selection is made and the latching mechanism (which consists of a trip latch and an intermediate latch lever) is tripped, permitting movement of the selected character pallet to a cocked position by centrifugal forces acting upon its counterweighted end. It is maintained in cocked position until it and its associated, cocked intermediate lever move, with rotation of the Wheel, into the triggering zone where the intermediate lever strikes an impact roller. Reaction of the intermediate lever causes it to instantly pivot and strike the counterweighted end of the associated pallet lever, causing it to pivot and strike the typewriter platen to print the character.

The intermediate lever serves a very distinct, as well as unique, purpose in that it absorbs all of the side thrust resulting when it strikes the impact roller. The force of impact is transferred through the intermediate lever as a pure radial operating impact on the type pallet lever, eliminating all of the lateral vibration tendencies which the type pallet lever would sustain if it directly impacted the roller.

Although all characters are seemingly printed on the fly, the typebar actually is stopped for a few microseconds during the actual printing operation. At the instant of printing, the type pallet wheel is, of course, in motion but, due to the impact force of the typebar hitting the platen,

the type face is, for an instant, buried in the resilient platen, thereby causing a slight bending of the typebar an instant before it begins to rebound away from the platen. After striking the platen to print the selected character the type pallet lever rebounds off the platen and returns to the type pallet wheel where it is again latched in the normal, inactive position. The type pallet wheel and the counterweighted levers that make up the printing and latching mechanism are relatively simple to fabricate and are, therefore, inexpensive. By eliminating magnets, springs, cams, and other component restrictions found in prior art pallet form of typewheels the typewheel has been kept light in weight, which in turn renders it capable of extremely high speeds.

Another unique feature of the construction of the type pallet wheel is the method in which it is mounted. It is a very simple matter to remove the head and replace it with heads of completely different type faces of other languages.

Accordingly, a primary object of the invention resides in the use of a unique continuously rotating type pallet wheel capable of very high speeds and able to print all. characters on the fly and in perfectly straight lines.

Another object of the invention resides in the provision of a combination printing apparatus including a continuously rotating type pallet wheel which carries the type pallets in such a manner as to cause them to rotate in a horizontal plane thus assuring continuous straight line printing at all times, a laterally shiftable carrier for the type pallet, and powered means on the carrier for driving: the carrier in character spacing steps and for carrier return movement.

Still another object of this invention is the provision of counterweighted type pallet levers which are actuated toward their printing positions by a stationary striker which is located in an interference position with the rotational path of intermediate levers of the typewheel assembly.

A further object of the invention is the provision of a continuously rotating type pallet wheel in which the type pallets levers are individually selected, unlatched and held in a cocked position by centrifugal force until this force is interrupted or disturbed by the interference of a striker roller located in the rotational path of the associated intermediate levers and these, in turn, strike the counterweighted ends of the type pallet levers causing them to move transverse to their rotational path to accomplish the print stroke.

Still another object of this invention is the provision of a continuously rotating type pallet wheel having individually selectable type pallets capable of such speeds of printing movement supplemental to rotational wheel movement as to cause selected type pallet levers to be moved through a supplemental printing stroke and back to a latched position so rapidly that a perfect character is printed on the record medium, completely smudgefree and sharp in outline. I

A further object resides in the provision of a novel mechanism and control structure to enable high speed character spacingof the type pallet wheel carrier. In conjunction with this object, it is a still further object to provide a type carrier return mechanism which utilizes control components and power components also used in the character spacing mechanism.

Still another object resides in providing a novel typewheel carrier character stepping and carrier return drive mechanism consisting of a rotating capstan drum on the carrier, control cables cooperating with the capstan drum, dual stop racks cooperating with the carrier and coordinated control components for the racks and cables to accomplish high speed carrier character spacing movements and carrier return movements.

Further novel features and other objects of this invention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings showing a preferred structure and embodiment, in which:

FIGURE 1 is a perspective and partially broken-away skeleton view of a typewriter embodying the present invention, the side plates being removed to expose primary mechanical features and the type pallet wheel being shown in exploded elevation above its normal operating position in order to expose details of the driving gear train;

FIGURE 2 is an enlarged perspective cut-away view of the type pallet wheel showing interior structural details;

FIGURE 3 is a perspective detail view of an assembly of one type pallet lever and its associated intermediate and latching levers showing their cooperative relationship in the type pallet wheel and also the kinematic relationship with the selecting mechanism;

FIGURE 4 is an enlarged detail of a vertical section through the type pallet wheel and shows one of the type pallet levers and associated levers disposed in a normal or latched position;

FIGURE 5 is an enlarged view similar to FIGURE 4, showing the type pallet lever shifted to the cocked position an instant after its associated intermediate lever has been unlatched by tripping of the associated latching lever;

FIGURE 6 is an enlarged view similar to but rotated 90 from the views shown in FIGURES 4 and 5, showing the type pallet lever at the instant of printing;

FIGURE 7 is a skeleton layout taken on a plane through line 77 of FIGURE 4 showing various positions of a latching lever as it progresses through its rotational path from a selected or tripped position to and past the position where it is cammed back to the latched position;

FIGURE 8 is a skeleton layout taken on a plane through line 8-8 of FIGURE 5 showing various positions of an intermediate lever relative to the latching lever as it progresses from the tripping point through its rotational path to the position where it strikes the abutment roller which causes it to actuate the type pallet lever and thence back to its latched position;

FIGURE 9 is a skeleton layout taken on a plane through line 99 of FIGURE 6 showing various positions of a type pallet lever as it moves from normal to cocked to printing positions and thence back to normal or latched position relative to both the latch lever and the intermediate lever positions shown in FIGURES 7 and 8 (and rotated 90 from FIGURE 6);

FIGURE 10 is a plan view of the typewriter mechanism of FIGURE 1 showing all components in their proper character spacing positions;

FIGURE 11 is a fragmentary detail view of the carriage return and line feed latching mechanism;

FIGURE 12 is a front elevation taken on line 1ll11 of FIGURE 10 illustrating the mechanical features associated with carriage return and line feed, some of the parts being shown partially cut-away or in phantom for better disclosure;

FIGURES 1316 are somewhat similar end views of the character spacing components, FIGURE 13 showing the components in a locked position, ready to be activated, FIGURE 14 showing the left hand stepping solenoid energized and its associated stepping rack rotated in a manner to allow the type pallet wheel carriage to move one character space to the right until it is stopped by a tooth on the other or second rack, FIGURE 15 showing the right-hand stepping solenoid energized and its associated stepping rack rotated in a manner to allow the type pallet wheel carriage to move another character space to the right until it is again stopped by a tooth on the first stepping rack, and FIGURE 16 showing both left and right hand stepping solenoids energized so both of their respective stepping racks are rotated out of engagement with the type pallet wheel carriage as they would be operated to enable a carriage return and line feed condition;

FIGURE 17 is an opposite end view to that shown in FIGURE 13 and shows the carriage return latching levers in normal position;

FIGURE 18 is an opposite end view similar to FIGURE 17, but illustrates the carriage return condition of FIG- URE 16 and shows the carriage return latching levers in a latched position to effect carriage return and line feed operations;

FIGURE 19 is a perspective drawing showing carriage return and line feed components in a character stepping position;

FIGURE 20 is a graphic timing chart showing the unlatch, print and space functions in a three-cycle sequence;

FIGURE 21 is a synchronous unlatch, print and space diagram showing the time allotments of each during two complete revolutions of the type pallet wheel; and

FIGURE 22 is a block diagram illustrating the printer of this invention combined with a diagrammatic keyboard and an electronic controller selector, the basic printer components being schematically illustrated within the printer block.

General Description The present invention pertains to a page printing mechanism which can be utilized as the printer in data communication equipment such as used in telegraphic and computer systems or the printer can be used as the typing portion of an electric typewriter. Whatever the configuration in which it is, the printer will utilize electric control signal pulses from a controller-selector unit which receives electrical coded signal information from a code transmitter of some type and coincidence information from the printer to provide appropriate control signals enabling a desired selection and printing of characters by the printer and control of the printer functions. Coincidence as well as some correlated and automatic printer functions such as automatic carriage return and start-ofline, ready condition are determined by the physical movements of the printer which results in feed back control signals to the controller-selectorunit.

The present invention, while intended for use with a transmitter and a controller-selector, does not include a transmitter per se nor a controller-selector per se. Nevertheless, to enable a more comprehensive understanding of the device, a block diagram of a keyboard transmitter 200, a controller-selector 202 and the printer 204 is included as FIGURE 22. The representative keyboard transmitter 200 is a multi-line code transmitter which transmits a code signal combination in the form of a group of bits in simultaneous transmission, however, a sequential bit transmitter could be used if desired, the sequential transmission being converted in a known manner, to simultaneous form in the controller-selector 202. Many known keyboards (tape reader or other device), capable of transmitting data symbols, corresponding for example to selected keys, by means of groups of electrical coded signal combinations are capable of use with this printer. Some examples of such keyboards are shown in United States Patent No. 2,982,810, or in application Serial No. 184,820, filed April 3, 1962. Depending upon whether the transmission is in simultaneous or in.sequential form, there are also many known forms of electrical or electronic control and selector apparatus which are capable of being readily adapted by one skilled in the art for utilization between a transmitter and the printer of the present invention. Several adaptable electronic control and selector apparatus with transistorized components and circuitry are shown in US. Patent No. 3,131,627 or in Serial No. 184,820, filed April 3, 1962. Combined as a single unit, the keyboard, the electronic control and selection device, and the printing apparatus can provide a high speed electric typewriter. If desired, an appropriate electronic storage circuitry will provide sufficient delay or buffer time to enable a carriage return function without loss of characters. One example of storage means can be seen in US. application Serial No. 829,446, filed July 24, 1959, now US. Patent No. 3,150,235.

The general organization and various details of the printer mechanism are illustrated in the perspective view, FIGURE 1 and other details are shown in FIGURES 2-19. Basic printer elements, as shown in the schematic portion of FIGURE 22 will provide a general idea of the printer mechanism.

There are many forms of continuous rotating typewheels available in the prior art and many of these accomplish printing in what is termed on-the-fiy, i.e., the typewheel continues rotation while printing occurs. As distinguished from the continuous rotating typewheel, the present invention utilizes a continuously rotating type pallet wheel which is supported on a carrier unit 17 mounted for sliding movement back and forth along the axis of a square shaft 18. A capstan type cable drive drum 100 is also journalled in the carrier unit 17 and along with the type pallet wheel 10 derives its rotation from rotation of square shaft 18. The square shaft 18 is continuously rotated by an electric motor 40 as long as the machine is turned on. Attached to and rotating with the shaft 18 are two electronic clock wheels 26 and 28. Clock wheel 26 is an indexed clock which pulses a reading head 30 while clock 28 is a type character position clock providing pulses into reading head 32. The pulses from the two reading heads 30 and 32 are directed into the electronic controller and selector to provide coincidence between incoming data information signals and the exact position of type pallets on the type pallet wheel 10 which correspond to those data information signals. At a precise point where the rotating type pallet wheel 10 moves a desired character to a selection station, the electronic controller and selector will impart a signal pulse over the print line to a type pallet selector magnet 46 which, through its armature lever, causes unlatching and cocking of the desired type pallet. Continued rotation of the type pallet wheel 11) results in mechanical camming action causing a transfer of operating force to the cocked type pallet lever, thereby accomplishes printing by impact of the type against an ink ribbon, a page record medium and a roller platen which can be seen in FIGURE 1 and will be further described hereinafter. Immediately after printing impact the type pallet lever becomes relatched in its inactive position.

Spacing occurs after each print function and can overlap the succeeding selection and cocking of the next selected type pallet, the electronic controller and selector transmitting a space pulse to a spacing solenoid 86 which tightens a fixed cable on the capstan drum 100 causing the drum and the pallet wheel carrier 17 to which it is attached to travel along the cable in a spacing direction. Simultaneously one or the other of racks 106 and 108, in alternate sequence will be tilted to permit the carrier 17 to be drawn one space to the right along the squar shaft 18 by the force of the rotating capstan drum 100. The spacing racks 100 and 108 are operated by means of control solenoid 88 and 90 which receive operating impulses simultaneously with the space pulse although, as was stated, the electronic controller and selector during spacing operation will only energize one or the other of the rack trip solenoids 88 and 90. This will be described in more detail hereinafter. Carriage return is accomplished in a manner somewhat similar to spacing excepting that a second cable, wound in the opposite direction on capstan drum 100, is tightened in response to a carriage return pulse from the controller-selector and simultaneously with that pulse both of the rack solenoids 88 and 90 are tripped to completely release the racks from the carrier 17 and enable the rotating capstan drum 100 to return the unblocked carrier to the istart-of-line position. Any carriage return signal trans- 1'3 mitted from the controller-selector will, in a conventional manner, block transmission of further print signals to the printer, however, when the carrier 17 returns to a start-of-line position, it will close a printer start-ready switch 176 which closes a circuit back to the electronic controller-selector informing it that print operations can again commence.

Specific description Referring primarily to FIGURE 1, most of the operat ing components of the printer mechanism are illustrated in somewhat skeletonized form. Although the major portion of the support frame work is omitted, the base plate and one side plate are illustrated. The type pallet wheel 10 is illustrated in exploded view, the phantom lines showing how the wheel would be disposed over its vertical support shaft 11. Shaft 11 is journalled in the carrier 17 and is directly drive coupled to a helical spur 12. The gear 12 is the center gear of a gear train con sisting of gears 12, 14, and 16, gear 12 being driven by gear 14 which is non-rotatably mounted, by means of a square aperture, on the square drive shaft 18. The drive gear 14, while rotated by shaft 18 is slidable therealong. Gear 14 rotates in a clockwise direction and therefore drives the gear 12 in a counterclockwise rotation as viewed in FIGURE 1. Square shaft 18 is continuously rotated by the drive motor 40 which furnishes the drive power imparted to the type pallet wheel 10. Shaft 11 and all three gears 12, 14, and 16 are mounted in suitable bushings in the carrier unit 17 (only partially shown in FIGURE 1) and the carrier with type pallet wheel and all three gears will move across the machine as a unit, supported on and guided by internal ball bearing mounts which slide on guide rods 20 and 22, rigidly fixed horizontally between the side plates of the printer frame.

The two ends of the square power shaft 18 are cylindrical, enabling the shaft to be suitably journalled and also enabling attachment of suitable pulleys and clockwheels on the square shaft. The right-hand end 24 of square shaft 18 carries two clockwheels 26 and 28 which are fixed to and rotate with the shaft 18. Associated with each clockwheel is a pick-up head or pulsing coil 30 and 32, respectively, which constitute a character indexing and position indicating mechanism for the ma chine similar to that which is illustrated and described in copending United States Patent 3,131,627 and aforenoted application Serial No. 184,820 assigned. to the assignee of the present invention. The magnetic fields around the ends of coils 30 and 32 are interrupted by notches 34 in the two clockwheels 26 and 28 and the resultant pulses trigger electronic circuitry in the controller-selector which searches and matches a selected character on the type pallet wheel 10 with an incoming code signal combination and upon determination of coincidence imparts an output signal pulse to the electro-mechanical selector mechanism 36 which selects the desired type pallet 38 by an unlatching or cocking operation at the exact instant when that type pallet assembly reaches a specific predetermined selection point in its rotation path. For each revolution of the type pallet wheel 10, 64 character pulses are provided by the character count clockwheel :28, one pulse for each of the sixty-four character pallets 3 8. Also, during each revolution of the type pallet wheel 10, two indexing pulses are provided by the index clockwheel 26 providing initiation of a countdown to 32 on each half of the type pallet wheel 10. The half (or side to be searched) is determined by electronic means in the electronic controlselector and is fully described in the aforenoted United States Patent application Serial No. 184,820.

The motor 40 is an AC. synchronous motor, trans mitting rotational motion to square shaft 18 through a toothed pulley belt 42 which encircles a drive pulley on the end of the motor shaft and a gear tooth pulley wheel 44 attached to the end 24 of square shaft 18.

As has been previously described, characters to be printed, are selected by means of a standard telegraphic keyboard or from a pre-p-unched tape (neither of which are detailed in the drawing) or from any similar source and code signals representative thereof are transmitted through circuitry in the electronic controller-selector into the typewriter or printer apparatus of the present invention.

Whenever a character is to be printed, code signal information is fed into the electronic circuits of the controller-selector mechanism. Simultaneously the pulses from the two clockwheels coils 3t) and 32 are directed to a coincidence detection circuit in the associated electronic cricuit of the selector. By this means the correct half of the type pallet wheel upon which the corresponding character pallet is located will be found and the selected character located. As soon as character coincidence is accomplished, the selector magnet 46, located on the carrier 17 is momentarily energized. Energization of selector magnet 46 occurs precisely when the selected character pallet 38 on the type pallet wheel reaches a specific predetermined point in its rotational path.

FIGURE 3 shows the linkage by which selector magnet 46 picks, unlatches and enables cocking of the selected character pallet 38. A magnet armature 4-8, mounted on a vertical pivot pin 49 on carrier 17, has suthcient rotational movement so that it can rotate counterclockwise on its pivot against the biasing force of a return spring 51 whenever the magnet coil is energized. A second spring 53 (which is much weaker than return spring 51) connects directly to the armature lever 43 and provides alight bias in the energizing direction of movement of the armature 48 which keeps the end 50 of armature lever snugly against the side of a notch 52 located in a selector lever 54, pivotally mounted on a vertical pivot post 55, also on carrier 17. The armature return spring 51 is anchored to carrier 17 and connects to the selector lever 54, biasing it in a retract direction against the force which occurs when selector magnet 46 is energized.

Selector magnet armature 48 is rotated counterclockwise upon energizing of the selector magnet 46 and its operating end 50 causes an instantaneous pivotal motion of the selector lever 54 in a clockwise direction against the force of the return spring 51. This movement occurs at the precise instant when the selected character pallet 38 reaches the predetermined selection point, and the nose end 56 of the pivoting selector lever 54 rapidly strikes a lower lug 57 of a latch 58 associated with the selected pallet lever, causing the latch 58 to rotate counterclockwise as seen in FIGURE 3.

Each of the 64 type character pallets 38 have associated therewith a latch member 58, an impact hammer 62 and a type pallet lever 66 the three named units of one such assembly being depicted in FIGURE 3. Sixty-four sets of the three units are located in a circumferentially equidistantly spaced apart arrangement in the type pallet wheel 10. With reference to FIGURE 2, the body of wheel consists of five ring shaped elements 210, 211, 212, 213, and 214, each of which include sixty-four vertical cut radially disposed comb slots. The lowermost ring 210 provides an annular series of guide comb plates 216 on the lower side. The next ring includes an outer peripheral ring of stop lugs 218 disposed over the slots between the guide comb plates 216. The sixty-four latches 58 depend down between the guide cone fingers 216 and are journalled on a pivot ring 59 which passes through all of the latches 58 and rests on top of the comb guide 216. The second ring 211, the one which contains the stop lugs 218, also contains guide combs 220 which in assembly over the lower ring 210 will be axially aligned with the lowermost guide combs 216. The lower edge of each of the comb plates 220 is notched, as shown in FIGURE 2, to embrace the pivot ring 59. Comb plates 220 provide a guide for the upper portion of the latches 58. The lower segment of the blocking lugs 218 serve as stop abutments for the released position of latches 58 as will be described.

The third ring 212 of the pallet wheel includes a hub portion 222 and a radial guide comb plate arrangement 224 consisting of 64 plates the spaces formed thereby serving to embrace the impace hammers 62. The impact hammers may carry individual pivot studs or as shown, can be threaded on a pivot ring 63 which rests on the upper edges of guide comb plates 221) of the second ring 211, the pivot ring 63 being located by notches in the lower edges of the third arrangement of comb plates 224. The comb plates 224, in assembly, are aligned with comb plates 220 and 216 of the lowermost rings 211 and 210. The three lower rings 210, 211 and 212 are secured together by screws 226 such as shown in FIGURE 4. The upper ends of the described abutment members 218 are formed as lugs which act as abutment limit stops for the impact hammers 62, such cooperation being shown in FIGURE 5 as will be fully described hereinafter.

The upper portion of the type pallet wheel 10 consists of a ring 213 which includes a hub portion 228 which is matched with and accurately axially aligned against the hub 222 of the lower portion by means of locator pins such as pin 230 shown in FIGURE 4. The ring 213 also includes a series of radial guide comb plates 232 which, upon assembly of the upper and lower portions of the type pallet wheel 10 are in axial alignment with the guide comb plates 224, 213 and 216. The uppermost edges of the comb plates 232 are notched to receive the pivots of type pallet levers 66 which may be individual pivots, or the pivot ring 72 which is shown in FIGURE 3. The uppermost ring 214 is placed on top of the type pallet wheel ring 213 and has pivot locking fingers 234 which overlie and retain the pallet lever pivot ring 72 in the notches of comb plates 232. Ring 214 is secured to ring 213 by means of screws 236 seen in FIGURE 4.

The complete type pallet wheel assembly is secured to shaft 11 by means of a square key 239, a nut 238, and a washer 240, shown in FIGURE 1. A keyway is milled in the inner-diameter of the two rings 212 and 213 and on the outer surface of shaft 11. Metal removed from the type pallet wheel 10 and the shaft 11 when the keyway is milled out will be replaced by the mass of the square key 239 so no appreciable imbalance will occur upon assembly of the wheel 10 on shaft 11. The mass of the type pallet wheel head with its group of 64 pallets, hammers and latches is a near perfect balance due to the equal distribution of the components around the periphery of the wheel and to the symetrical construction of the various rings which make up the body of the type wheel 10.

Returning to FIGURE 3, when the selector lever 54 has been actuated by the selector magnet 46 so that its tip end 56 impacts the lower end 57 of a latch 58, the latch 58 will then be rotated on the pivot 59 (see FIGURE 5 so an upper lug 60 on the latch 58 moves counterclockwise away from a blocking cooperation under a latching shoulder on the associated impact hammer 62. The shape of impact hammer 62 is more accurately shown in FIGURES 4, 5, and 6, however, in FIGURE 3 it will be seen that the major mass of the hammer is situated above its pivot 63 so as soon as the latched shoulder 85 is unblocked by movement of latch 58 away from latched condition, the mass of the impact hammer 62 under centrifugal force causes it to swing counterclockwise or out to a limit position caused by abutting the upper end of an abutment finger 218. The centrifugal forces are created by the rotating type pallet wheel 10. The slight counterclockwise rotation of the impact hammer 62 releases a retaining force on the lower end 68 of an associated type 9 cocked condition of the type pallet lever and impact hammer.

Upon being rotated clockwise on its pivot '72 the selected type pallet lever 66 will shift its type pallet 38, on its upper end, in toward the center of the type pallet wheel 10. This position is maintained by the centrifugal forces throughout the major portion of the operational cycle which preceeds the actual print operation. There is no start-stop operation involved in any phase of the present inventions printing cycle other than that which occurs when the machine is shut down during nonoperative periods. All the operationssuch as searching, selecting and printing are accomplished on-the-fly and even the machine functions such as line feed and carriage return are accomplished while the type pallet wheel 10 is in continual rotation.

When a selection operation has resulted in tripping of the desired latch 58 and the associated impact hammer 62 is permitted to swing out and unblock its type pallet lever 66, the upper impact end 64 of the impact hammer has shifted out to its cocked limit position where a vertically disposed edge portion 67 is projected beyond the outer diameter of the guide comb 224 of center ring 212 a distance of about inch, shown in FIGURE and at the bottom and right-hand side of FIGURE 8.

The rotating type pallet wheel carries the selected and cocked hammer and type pallet 38 around toward the printing position (top of FIGURE 9), and an instant prior to the print position, the edge projection 67 of weighted end 64 of the selected impact hammer will hit an impact roller 78 which is mounted on a bracket 77 secured to the carrier unit 17 (FIGURE 6). Roller 78 is located in the rotational path of the impact hammer projection 67 with its axis on the exact center line of the printing position. Due to the diameter of the impact roller 78, the cocked hammer projection 67 will contact the impact rollers 78 a slight distance ahead of the print position or, in terms of time, a fraction of a second before it reaches the center line of the printing position and the resultant camming action forces the hammer toward the axis of the pallet wheel 10. Thus it is clear that variations in the diameter of the impact roller 78 can eifect print timing and accordingly it must be held within certain limits if printing is to be accomplished at the precise center of the desired printing position. It is also obvious that the roller 78 could be made with a slightly smaller or larger diameter which would cause printing to occur earlier (for the larger diameter) or slightly later (for the smaller diameter), yet in both cases the printed characters will still be printed in a straight line and properly spaced from one another, although the characters would have a tendency to be more heavily printed on one side than on the other.

As is intentionally depicted in FIGURE 6, the mounting portion '79 of the journal stud which carries the impact roller 78 is made eccentric to the roller axis. Such eccentricity is often used in printing telegraph and typewriter mechanism to enable fine adjustments between coacting parts. In this case, adjustments to bring the print position to a proper perpendicular path between the pallet wheel 10 and platen 91 can be accomplished by shifting the eccentric mounting of the roller journal stud 79 or it could be accomplished by interchanging various diameter rollers.

When the edge 67 of a cocked impact hammer 62 hits the impact roller 78 and the hammer is driven in toward the center of type pallet wheel 10, it in turn, being in contact with the weighted end of the selected type pallet lever 66 transfers the impact force to the lower end 68 of the cocked type pallet lever 66. That lever 66 will then be instantly pivoted counterclockwise about its pivot axis 72 and the type pallet 38 on the upper lever arm 70 moves out and strikes an inked ribbon 80 which is pressed against a page or sheet of paper 82 backed by the it platen roller 91, resulting in printing of the selected character (see FIGURE 6).

The foregoing description explains selection, cocking and printing movements of the individual type pallet linkage sets. In FIGURE 6, a curved cam plate 84 can be seen upstanding from the carrier unit 17. It is located under the pallet wheel 10 and radially within the path of rotation of the lower fingers 57 on latches 58, and cooperates with the latches to place them in relatch condition. The radial cam pattern of cam 84 is shown in FIGURE 7.

While the printing operations are occurring, several other functions are also being accomplished in order to enable relatching of the type pallet linkage set which was selected and operated. An instant before a cocked impact hammer strikes the impact roller 78, the associated latch 58 which was previously tripped by selector lever 54, enters what might be termed the operative zone of the relatching cam 84 (see FIGURE 7). When the impact hammer strikes impact roller 78 and is pivoted clockwise on its pivot 68, its lower end with latch notch 85, is lifted above the path of the latch arm 60 of the associated latch 58 (see FIGURE 6). The latch 58, at this instant is in the process of being cammed to its latching position and completes a camming movement back to its normal latch position without being obstructed by the impact hammer. Upon impact with roller 78, the impact hammer 62 was forced back toward the center of the type pallet wheel 10 due to elastic rebound forces and will continue in its rebound path until an integral abutment stop 8'7 strikes the inside wall 89 of the type pallet wheel ring 212, as shown in FIGURE 6, whereupon it rebounds in the reverse direction, CCW causing its notched latch end to engage and come to rest on the latching lug of latch 58 which is being maintained in its latching position by cam 84. Now the impact hammer will be maintained by a centrifugal bias force in this latched position, as previously described, and an instant later the latch 58 passes away from control by the relatching cam 84. The relatched type pallet linkage set is again ready for subse quent selection when desired.

The type pallet lever 66, while the above relatching action has occurred, underwent a rebound in the clockwise direction to its normal limit position (after striking the platen 91) determined by the lower end 68 engaging the weighted end of impact hammer 62. Centrifugal force on the lower massive end of the pallet lever 66 will hold the lower end outwardly in rest position against the impact hammer 62 where it is maintained until that linkage set is again selected.

As has been previously described, the long upper arm of the type pallet lever is relatively thin and provides a resilience in the direction of rotation, so that the type pallet 38 upon impact against ribbon, paper and platen can be momentarily stopped from movement in a rotational path even though the pivot portion and the lower end 68 of the pallet lever 66 continue normal rotation.

Character spacing To accomplish character spacing, and also backspacing and carriage return which will be more fully described hereinafter, a unique stepping apparatus is provided to enable movement of the carrier unit 17 under power in both directions. Stepping is controlled by electrical pulse signals, from the selector electronics, generated in a timed relationship with the printing operation. To utilize the electrical pulses, the stepping apparatus includes three control solenoids seen in FIGURE 10, one of which, a stepping cable solenoid 86, being invariably pulsed for each spacing step and the other two, solenoids 88 and 90 being pulsed one at a time in alternate sequence for successive spacing steps. Whichever one of solenoids 88 and 90 is pulsed, the pulse occurs simultaneously with pulsing of the stepping cable solenoid 86.

The stepping cable solenoid 86 controls the drive force which shifts the carrier unit 17 horizontally along its guide rails 20 and 22, drive force being derived by tightening a cable 96 which is looped around the periphery of a capstan wheel 100. Turning momentarily to FIGURE 1, it will be recalled that a gear train consisting of gears 12, 14, and 16, is mounted on the carrier unit 17 and that all three gears are continually rotating due to rotation of the square shaft 18 by the machine motor. Going back to FIGURE 12, gear 16 of that previously described train of gears is shown as journalled on a depending stub axle 99 secured in a portion of the carrier unit 17. The capstan wheel 100 is rigidly secured to and under the gear 16 for rotation therewith, thus capstan wheel 100 will be in continuous rotation during operation of the machine.

The stepping cable solenoid 86, FIGURE 10, is arranged with its plunger 92 moving in a path parallel to that of the carrier unit 17. The end of plunger 92 is pivotally connected to one arm of a lever 94- pivotally journalled on the printer base plate 99 on an upright axis. The other arm of lever 94 constitutes a cable anchor 93 and anchors one end of a stepping cable 96 which stretches substantially horizontally past the front of the capstan wheel, loops around the upper capstan wheel groove 98 one time and continues its stretch to the right hand side of the printer where its right hand end is anchored to the free end of a tensioning lever 101 which in turn is pivotally secured to the base plate 99. The lever 101 abuts an adjustment screw 103 and is spring biased by means of a spring 105 so that the lever 101 is held against the adjustment secrew 103 when the stepping cable 96 is slack or not in use. When the stepping solenoid 86 is pulsed, its plunger 92 is drawn inward, rotating lever 94 and pulling the stepping cable 96 taut, locking its loop tightly around the groove 93 in the capstan wheel 100. Due to the direction of rotation of capstan wheel 100 the entire carrier unit 17 will be pulled along the cable 96 toward the right side of the machine.

The extent of stepping movement of the carrier unit 17 although powered by the tightening of the stepping cable 96 is controlled in positive increments by two Stepping racks 106 and 108. Racks 106 and 108 are secured on rocking shafts S and 107 suitably journalled in the machine side plate 109 and a bracket 111. Bell cranks 113 and 115 rigidly fixed to the ends of shafts 105 and 107 are pivotally connected to the plungers of rack stepping solenoids 88 and 90 respectively. Although not shown, the stepping solenoids 83 and 90 are secured to the outer side of support plate 109 so that upon energization the plungers will move upwardly and through means of the associated bell cranks 113 or 115 will pivot the associated rack 106 or 108 down away from the carrier unit 117. A tension coil spring 138 interconnects the two lower ends of bell cranks 113 and 115 creating a bias force urging the two racks into an engaged position with a rectangular stop lug 112 which is secured to the lefthand edge of carrier unit 17. The upper edge portion of each of the two stepping racks 106 and 108 which is engaged by the stop lug 112 have alternately positioned upstanding teeth 110 which provide stop abutments for engagement by the lower edge of the stop lug 112 upon horizontal movement of carrier unit 17 Due to the alternate and staggered arrangement of the teeth 110 on rack 106 with the teeth 110 on rack 108 only one tooth of one of the racks is actually abutted by the carrier stop lug 112 at any one time.

FIGURES 13, 14, and illustrate, respectively, the two racks 106 and 108 disposed in normal position (FIG- URE 12), stepping solenoid 88 pulsed and rack 106 lowered away from engagement with the stop lug 112 (FIG- URE 14), and a similar rocking of rack 108 by the pulsing of solenoid 90 (FIGURE 15). During a stepping operation, the two rack solenoids 83 and 90 will be alternately pulsed through an electronic flip flop circuit located in the electronic selector mechanism.

Although the stepping cable 96 is considered to be normally in slack condition, the adjustment screw 103 and biasing spring 105 coacting with the tension lever 101 enables sufficient tautness of the cable 96 to create a slight bias urging the carrier unit 17 toward the right so that the stepping lug 112 will always have a slight bias to the right causing it to abut the left-hand side of one of the rack teeth 110. The arrangement represented in FIG- URE 13 illustrates the stop lug 112 in abutment against one of the teeth on rack 106. Under such condition when a spacing step is signalled from the electronic selector the stepping cable solenoid 86 will be pulsed, tightening the stepping cable 96, and at the same time the one rack solenoid 83 will be pulsed to rotate bell crank 113 clockwise, rocking its rack 106 to move the engaged tooth 110a down below the edge of stop 112. Due to thesimultaneous tightening of the stepping cable 96, carrier unit 17 will now be forced to the right until the stop lug 112 abuts the side of tooth 11% on the opposite stepping rack 108 (see FTGURE 14). Upon the next spacing step the stepping cable solenoid 86 will again be pulsed but this time the other stepping rack solenoid 90 will be energized and its bell crank 115 will be rocked to rock its stepping rack 108 disengaging the tooth 11% and permitting the carrier unit to move one step further to the right until the stop lug 112 abuts the next tooth on rack 106. In this manner alternate printing and stepping of the type pallet wheel 10 will continue as long as signals are transmitted from the electronic selector mechanism to the machine or until the carrier unit reaches its limit position at the right hand end of the machine.

Carriage return A carriage return function can be accomplished either automatically or by manual means, in both cases the control being accomplished through the electronic selector mechanism. Within the electronic selector mechanism the aforementioned flip fiop circuit (not shown) which causes alternate pulsing of the two stepping rack solenoids 88 and 90, will be bypassed or overcome by suitable electronic circuitry in a manner well known to those skilled in the art, so that both solenoids 88 and 90 can be pulsed at the same time. The following description will concern the structure enabling carriage return and will explain how automatic carriage return is accomplished.

Again, turning back temporarily to FIGURE 1, a tripping bracket 114 can be seen secured to the right hand corner of the carrier unit 17. The bracket 14 is so located that when carrier unit 17 reaches the extreme right limit of travel, the end of line position, the bent end of bracket 114 engages the actuator of an automatic carriage return switch 116 which is mounted on the frame plate 102. When the automatic carriage return switch 116 is closed, it will close a circuit to appropriate components in the electronic selector (FIGURE 22) which immedi ately sends a pulse to energize a carriage return solenoid 118 secured near the right hand front edge of base plate 99. At the same time, the selector circuits will bypass the stepping solenoid flip flop circuit and simultaneously send pulses to both of the stepping rack solenoids 88 and 90. This simultaneous energization of the two stepping rack solenoids causes immediate rocking of both stepping racks so the teeth 110 of both racks are lowered out of the path of movement of the carrier unit stop lug 112. Since the stepping rack solenoids 88 and 90 are only momentarily pulsed, an automatic latching mechanism is provided at the left hand end of the two stepping racks to hold them in a disengaged position. The rack latching linkage can be seen in FIGURES 10, 12, and 17 through 19. FIGURE 16 illustrates both of the racks 106 and 108 being simultaneously rocked away from engagement with the stepping lug 112.

The rack latching mechanism consists of levers 122 and 124 rigidly attached to the left-hand ends of the rack shafts 105 and 107 respectively. In the normal position of the two racks 106 and 108, the end levers 122 and 124 as shown in FIGURES 17 and 19 extend horizontally and rest on the upper edges of the two side arms of a U-shaped bracket 128 pivotally supported on the base plate 99. A side view of the bracket 128 can be seen in FIGURE 12 which also shows a biasing spring 126 connected to the bight of the U-shaped bracket 128 urging it to rotate on its pivot 130 so its side arms are pressing up against the lower edges of the two levers 122 and 124.

The two arms of U-shaped bracket 128 have notched stop abutments 134 at the ends of their upper surfaces. The notches constitute step shoulders 132 (see in FIG- URE 12) on each side of the bracket 128. When the two solenoids 88 and 90 are simultaneously pulsed and the two racks thereby simultaneously rock, as shown in FIGURE 18, the outer ends of the two levers 122 and 124 are both raised a sufficient distance so that bracket 128 can be rocked by the biasing force of its spring 126 placing the two stepped shoulders 132 under the ends of the rack latch levers 122 and 124, the position illustrated in FIGURE 18. The vertical portions of the two notches which are the stops 134 and 136 limit the rotation of bracket 128 when they abut against the two levers 122 and 124. Both stepping rack solenoids 88 and 91) at this point become de-energized and their biasing spring 138, seen in FIGURE 13 and which is stronger than the U-shaped bracket biasing spring 126, urges the return of the two stepping racks 106 and 108 to their normal operative position relative to the stop lug 112. The racks however cannot return because their two levers 122 and 124 are latched on the steps 132 of U-shaped bracket 128. This operation completely unblocks the carrier unit for horizontal travel back to the left-hand margin or start-of-line position. The return mechanism which drives the carrier unit 17 to the start-of-line position will now be described.

Shown in FIGURES 10, 11, and 19 the carriage return solenoid 118 is located with its plunger 139 projecting toward the righthand side of the machine in a horizontal path. The end of plunger 139 is pivotably attached to a control lever 140 which is mounted on a vertical pivot post secured in base plate 99. The opposite end of lever 141) includes a cable anchor 148 to which is secured one end of a carriage return cable 150 which stretches to the left horizontally behind the capstan wheel looping once completely around the lower groove 152 of the capstan wheel and passing on horizontally to an anchor position in the end of a biasing lever 154 shown in the upper left-hand corner of FIGURE 10. The biasing tension lever 154 is under the tension of a coil spring 151 and is rendered adjustable by means of an adjustment screw 153 providing an arrangement similar to that of the stepping cable to hold the carriage return cable 150 in a semi-taut condition during its inoperative periods. At an intermediate position on the carriage return lever a short latching arm 144 projects toward the left side of the machine. When the return solenoid 118 is energized by a carriage return pulse, the latch arm 144 shifts clockwise with the movement of lever 140 its terminal end cooperates with a latch pawl located on a latch lever 146 which is biased in a counterclockwise direction by means of a previously described U-bracket biasing spring 126. Clockwise movement of the carriage return lever 140 moves the latch arm 144 past pawl tooth 145 and the latch lever 146 will snap into latching position preventing the return movement of the carriage return lever 140 after the energizing pulse terminates. This latched position of lever 140 maintains the carriage return cable in the taut condition, in which it must remain for a sufficient period to permit the carrier unit 17 to be fully returned to the left-hand margin of the machine.

When the carriage return solenoid 118 is energized to pull and latch the carriage return cable 150 taut, the

continually rotating capstan wheel 100 will roll along the tight cable and propel the carrier unit 17 toward the left-hand margin of the machine guided by the guide rods 20 and 22. During the final portion of travel of carrier unit 17, just before it reaches the left-hand margin, it will be decelerated by a unit 157 illustrated in FIG- URE 1. The left-hand margin of carrier unit 17 will abut an upstanding lug on a deceleration lever 155 the end of which is pivotably connected to the plunger of the dash pot 157. The deceleration prevents destructive impact forces which could result upon the rapidly moving carrier unit reaching the end of its travel. At this point, in other words, when the carrier unit reaches its start-ofline position the racks must be released to return to their normal stepping control positions and the carriage return cable 151) must be immediately slackened to remove the drive force. The manner in which this is accomplished will now be described, it being noted at this point that manual carriage return is accomplished in the exact same manner as that described for automatic carriage return except that the cycle will be started by depressing a key on the key board of the transmitter, the key operating the switch which accomplishes the same function as the automatic carriage return switch 116.

To disable the carriage return operation, a tripping rod 156 (seen in FIGURES 1, 10, 11, 12, and 19) is mounted in small angle brackets 166 secured near the front of the base plate. The tripping rod 156 is disposed parallel to the horizontal path of movement of carrier unit 17, and below a portion of the carrier unit, being guided in the angle brackets 166 for axial shift. Four levers or lugs, seen in FIGURES 10 and 12, are rigidly secured on the tripping rod. Levers 158, 162, and 164 project toward the rear of the unit whereas the intermediate lever projects toward the front of the machine. Adjacent the right-hand end of rod 156 a coil compression spring 168 coacts between one of the brackets 166 and the right-hand tripping lever 164 to create an axial biasing force urging the tripping rod to its normal position, the position shown in FIGURE 10. The leftmost tripping lever 158 extends into the path of movement of the carrier unit 17. The intermediate tripping lever 160 extends forward into the path of movement of the plunger of its solenoid 188 to be later described and has an axial shifting movement which enables it to engage the operating unit of a switch 176 to be later described. The position of tripping lug 162 enables it, upon axial shift to the left, to engage a lug 172 integral with the aforedescribed U-shaped bracket 128 which latches it to racks 106 and 108. The righthand tripping lever 164 upon axial shift of the tripping rod 156 moves in a path which engages the tip end of latch lever 146 which has been described. as a means for latching the carriage return cable in its taut condition.

As the type pallet wheel 10 carried by the carrier unit 17 approaches the start-of-line position at the left side of the machine, a small angle bracket (seen in FIGURE 12), located on the lower side of the carrier unit 17 engages the left-hand tripping lever 158 and carries the tripping rod 156 axially to the left. This simultaneously shifts the other three tripping levers secured to the tripping rod 156.

The right-hand lever 164 will hit the end of latch lever 146 moving it counterclockwise to release the latch pawl 145 from the latch arm 144 of carriage return lever 140. Lever 140 will be instantly rotated counterclockwise back to its inactive position by means of the spring 142, thereby removing the tension of the carriage return cable 150 and permitting restoration of the carriage return solenoid plunger 139 to a normal deenergized position adjacent the adjustable stop 171.

Tripping rod lever 162 which is also moved to the left engages the lug 172 on the U-shaped bracket 128, rotating the bracket 128 counterclockwise as seen in FIGURE 12 until the steps 132 are removed from below the rack levers 122 and 124. Levers 122 and 124 upon being released will immediately permit rotation of the two racks 106 and 108 back to a normal carrier stepping condition where both levers 122 and 124 rest on the top surface 174 of the U-shaped bracket 128. At this time the first tooth 110, located in the example on rack 106, is once again in the path of and subject to engagement by the carrier stop lug 112 and since the carriage stepping cable 96 always creates sufficient force on the capstan wheel 100 to provide a slight biasing force of the carrier unit 17 toward the right, the carrier spacing stop lug 112 will be urged into contact with the first rack tooth 110.

During a carriage return operation, it is conventional practice to provide a circuit in the electronic selector apparatus which will inhibit the sending of signals for printing characters to the printer unit until the carriage return operation is completed. Some of the electronic selector mechanisms illustrated in the aforedescribed patents and applications have sufficient provision for automatic storage of characters which are received during the interval of a carriage return to prevent loss of such characters and normally the selector mechanism requires a signal from the printer indicating that it is again in condition for receiving print information. To provide such a signal the intermediate trip lever 160 is so disposed that an incremental instant following the actuation of functions by the other levers 158, 162, and 164 the lever 160 will engage and close the switch 176 closing a circuit which signals the selector mechanism that the type pallet wheel 10 is again in the proper start-of-line position to resume printing operations along with next line of the page. This delayed ready signal action of lever 160 is necessary to assure that the type pallet wheel 10 is fully returned to the left-hand margin of the machine before the next printing cycle commences. A small guide rod 177 attached to lever 160 slides in a guide hole in the associated bracket 166 to stabilize the tripping rod 156 and prevent its turning, i.e., the tripping rod is prevented from rotating and thereby maintains levers 158, 160, 162 and 164 in their properly aligned positions.

The next character signal combination is then sent to the electronic selector mechanism or a control pulse sent from the selector mechanism to the printer. Selection of and printing by the desired type pallet lever 66 will be completed in a manner as previously described. After the first character of the new line has been printed, the stepping rack solenoid 88 will be pulsed together with the stepping cable solenoid 86 and the type pallet wheel 10 with carrier 17 is moved across the machine one charac ter space. This initial action will in turn cause the carrier plate angle bracket 170 to be shifted away from the left hand tripping lever 158, which releases the tripping rod assembly 156 enabling its compression spring 168 to shift it back toward its normal position a distance sufficient to move the lever 160 away from the actuator of ready signal switch 176 permitting that switch to open. After printing of the next character, the tripping rod assembly 156 is completely released and returns to its normal inactive position.

The Line Feed Function is either automatic or manual and can be of any conventional type such as found in most telegraph page printers and, therefore, will not be described. Automatic line feed will, of course, be arranged to occur immediately on initiation of the return of the carriage 17 to the left hand margin and manual line feed will be accomplished by depressing a line feed key on the keyboard.

Backspace The backspace function is operated by depressing a backspace key on the keyboard. In this function the solenoids for the two stepping racks 106 and 108 are alternately pulsed for successive backspace operations just as in normal stepping operations except that in this function the carriage return solenoid 118 is pulsed simultaneously with the one stepping rack solenoid 88 or 90. Thus, when one stepping rack 106 moves out of engagement with the carriage 17, the other stepping rack 108 remains in engagement and, at the same time, the carriage return solenoid 118, being instantaneously pulsed, pulls the carriage return cable 150 taut on the capstan wheel 100 which moves the carriage 17 back one character space where it is then stopped when its attached lug 112 hits a tooth 110 of the engaged stepping rack 108.

After the carriage 17 has been properly back spaced the desired number of spaces, normal stepping operations are resumed when the next character or spacing pulse is sent to the machine.

Tabulating The tabulation mechanism 184 in this invention is of a conventional type widely used in telegraph page printers and typewriters today and is only generally illustrated in FIGURE 10. It utilizes three controlling keys, a tab set key, tabulating key and a tab clear key (not shown but all located on the keyboard).

The tabulating function is set into operation by depressing a tab set key just as it is done in conventional typewriter mechanisms. After the tabs have been set up, normal operation can proceed until tabulation is needed.

When the tabulating key is depressed, the stepping rack flip-flop circuit in the electronic selector mechanism is overcome or bypassed and both stepping rack solenoids 88 and 90 are pulsed simultaneously lowering both stepping racks 106 and 108 so that neither are engaged with the lug 112 on the underside of the carriage 17. A tab solenoid 186 secured on carriage 17 is pulsed and held and the stepping cable solenoid 86 is simultaneously pulsed with the two stepping rack solenoids 88 and 90, pulls the stepping cable 96 taut, tightening it on the capstan wheel 110 and thereby causes the carriage 17 (to which the capstan wheel 100 is attached) to move toward the right hand margin until it is stopped by the tab solenoid plunger lug 187 engaging the next (previously selected) set tab in the tabulation mechanism 184.

At this point the two stepping racks 106 and 108 will have automatically become and will remain latched by bracket 128 in the disengaged position, however, the tab solenoid 186 remains energized. The racks 106 and 108 will remain latched until released when the next character pulse or space pulse is sent to the machine. The previous operation of the tab key will energize circuitry in the electronics which enables pulsing of a special stepping rack unlatching solenoid 188 and deenergizing of the tab solenoid 186 whenever the next character or space pulse is received. The unlatching solenoid plunger 200 hits the lever 160, moving it toward the left. Lever 160, being fixed to the tripping rod 156, causes the tripping rod 156 to move toward the left also, and lever 162, also attached to the tripping rod 156, moves toward the left and strikes arm 172 of the U-shaped bracket 128, rotating the bracket 128 which unblocks the two stepping racks 106 and 108 in a manner as has been previously described, and the carriage can step to the next position as determined by the appropriate ing on the two racks.

Normal stepping of the carriage 17 will then commence again and it will be stepped along unless the tab key is again pressed whereupon the carriage is moved to the next tab stop in the tabulating mechanism 184 and the above tab stop release operation will be repeated. This tabulating operation may continue until the carriage 17 reaches the right hand margin and trips the carriage return switch 116. The carriage will then be returned to the left hand margin in the normal carriage return operation. Spac ing and carriage return pulses will always disengage the tab solenoid 186 so that the carriage 17 can he stepped by normal pulses and returned in a normal carriage return function without disturbing the selected tabulation set-up.

The linked ribbion 80 and associated advancing and reversing mechanism is also of the conventional type, well known t0 those familiar with the art and will not, there- .17 fore, be dealt with in any great detail. The ribbon 80 passes from one spool 178 (see FIGURE 1), over the guide rollers 180 and 182, across the platen 91 and through the guide yoke 186 to a second spool (not shown). The ribbon 80 is wound on this spool and at a specific point it is reversed and rewound on the opposite spool 178 again by a reversing mechanism of the conventional type.

Timing The simplest timing cycle of printer operation will be to utilize two rotations of the pallet wheel for each cycle of coincidence determination, selection, printing and spacing. Coincidence determination requires up to 360 of rotation and a start index position to cover all of the different pallet or character locations around the periphery of the type pallet wheel. Selection will be substantially concurrent with coincidence determination because of the rapidity of electrical pulse transmissions resulting from an indication of coincidence between position and the received signal in the electronic selector.

Since printing follows a selection and is mechanical, the mechanism requires a time lag from the point of actual selection to the point where the print stroke occurs. This time lag permits mechanical shifting of the selected pallet linkage set to a cocked position. Thus a print stroke following a selection will always occur after the typewheel has been rotated through a fixed angle of rotation (equal to a fixed number of selection positions), after the point of selection.

In the exemplary device, as apparent from FIGURE 7, the fixed angle, or degrees of rotation between the selection point and the print point is approximately 270. Since coincidence determination of a character in 64th position could require 360 of rotation, a complete operational cycle requires 360 plus the 270 to print position, more than one rotation and no more than two rotations of the pallet wheel must be available for a complete cycle. Spacing steps must occur subsequent to a print stroke and can be triggered, through a time delay circuit in the electronic selector, by the same pulse which is used for selection. If the spacing pulse is delayed for 25 milliseconds following a selection pulse, the type wheel rotating at 1800 r.p.m. will have rotated 270 and the print stroke will have occurred at the same instant the spacing step is initiated.

As illustrated by the timing diagram of FIGURE 20, if coincidence is determined during every other rotation of the typewheel, which can be accomplished in a known manner by using appropriate electronic logic and indexing pulses, the delayed print stroke will occur at some point within the latter portion of the 360 coincidence rotation and the initial portion of the intervening 360 rotation before the next coincidence rotation period begins. This occurs regardless of which character pallet linkage set is selected so that printing of the selected character is always accomplished before the next coincidence determination count is started.

The shortest period between print strokes is that which elapses between printing of the 64th character and an immediately successive printing of the first character (considering character position on the pallet wheel). In other words, the time required during this shortest period is necessary to accomplish 1% revolutions of the pallet wheel. The longest period between print strokes is that which elapses between printing of the first character and an immediately successive printing of the 64th character, in other words, the time required for 2 revolutions of the drum. Since the time required for accomplishing the mechanical spacing operation requires less than the time (33 /3 milliseconds) for one revolution of the pallet wheel, and because the mechanical space step is initiated at approximately the same instant that a print stroke occurs, spacing will always be completed well within the shortest allotted time between print strokes which is at least the time required for one and revolutions of the pallet wheel.

The timing chart shown in FIGURE 20 covers four cycles of printer operation and shows five functions which occur during a print cycle. The five conditions, from top to bottom, represent electronic coincidence deter mination, electro-mechanical selection and cocking of a character pallet linkage set, the mechanical print stroke and the spacing operation consisting of the delayed electronic space pulse and the electro-mechanical spacing operation. Each cycle covers two revolutions of the pallet wheel and therefore extends horizontally for 720. The shaded area extending along each line represents the period during which that operation can occur, it does not mean that that operation requires that amount of time to accomplish the function. For example, coincidence determination could occur on the first count as is represented by the superimposed symbols in the first cycle of operation shown in FIGURE 20. In such case, coincidence determination occurs substantially at the start of the cycle and selection, which follows immediately also occurs near the start of the cycle. Approximately 270 later the mechanically actuated print stroke occurs. As clearly depicted on the chart the print stroke for the first character occurs at the start of the period during Which any selected print stroke must occur, however, the print stroke requires only a minute fraction of the entire period.

The mechanical spacing operation requires the longest period of time and Will occur during a period which falls within the narrow shaded area. If the first character has been selected, the space initiating pulse will occur at the beginning of the narrow space period and will be completed within 360 of rotation of the type pallet wheel.

The second example shown on the chart of FIGURE 20 represents a printing operation of the last or the 64th character on the wheel. Here, coincidence determination occurs at the end of the coincidence period, i.e., after 360 of rotation of the type pallet wheel. Again, selection occurs substantially at the same instant which is at the end of the available selection period. The print stroke occurs 270 later which is at the end of the available print period and almost instantaneously the spacing operation is initiated. Note that the spacing operation occurs during the latter portion of the period represented by the shaded area where spacing can occur and in this instance will overlap into the next printer operation cycle but the spacing function still does not extend to the point where the next print stroke will occur.

Third cycle represented in FIGURE 20 again repeats an operation for selection and printing of the first character on the printing wheel. The three representations of selection and printing, superimposed on FIGURE 20, illustrate the longest lapse, or worst time, between a printing of the first character and a printing of the 64th character and also the shortest lapse, or best time period, which occurs between successive printing of the 64th character and the first character. It can also be seen that a mechanical spacing operation can be occurring during the portion of the next cycle when coincidence is being determined, but spacing must invariably be completed before the next print stroke occurs.

The actual arrangement of selection circuits will depend upon the logic which is desired to be used in connection with the operation of the printer and in this area different modes of operation can depend upon the designer. The foregoing timing representation does represent one way in which it can be accomplished but it is not intended to preclude other manners of operation. For example, coincidence could be determined instantaneously rather than waiting for a full count and then, with an appropriate delay to enable the time lag for spacing, the next print operation could occur immediately following completion of the space step which would shorten the time periods considerably between print operations, however, the logic and circuitry for such a selector mechanism would be more complex. Another manner in which the time periods between printing could be considerably shortened would be to increase speed of the pallet wheel by increasing the gear ratios of the gears plus a general beefing up of the power train and motor. The time for a spacing step would be decreased as a result of using a more powerful motor plus faster solenoids to tighten the stepping cable and operate the stepping racks. However, this invention pertains to the printer mechanism per se and not to any specific. form of logic or selector mechanism.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. A power driven typewriter or the like machine comprising:

a frame structure;

a platen on said structure for providing backing for a record medium;

a carrier mounted on said structure and shiftable back and forth in front of said platen between start-ofline and end-of-line positions; means connected to said carrier to shift said carrier;

print mechanism mounted on said carrier; and

power means on said structure including a rotatable element on and shiftable with said carrier connected to at least a portion of said means to shift said carrier and to at least a portion of said print mechanism providing a power source for printing and for carrier shifting movement.

, 2. A power driven typewriter or the like machine comprising:

a frame support structure,

a print mechanism carrier, print mechanism mounted on said carrier,

means mounting said carrier on said support structure for shifting movement of said carrier enabling character spacing of said carrier and return of said carrier to start-of-line position,

continually rotating means on and shiftable with said carrier,

selectively operable control means secured to said structure and having a portion in engagement with said continuously rotating means for enabling power to be derived from said continually rotating means to accomplish character spacing and return to startof-line movements of said carrier, said print mechanism being connected to said rotating means and deriving its actuating power therefrom.

3. A power driven typewriter comprising:

a frame structure;

a print mechanism carrier mounted for shifting movement in opposite directions on said frame;

a first rotatable member rotatably mounted on said carrier;

a plurality of character printing means carried by said first rotatable member;

a second rotatable member on said carrier connected -to and rotatable with said first rotatable member;

power means on said frame structure;

drive means connecting said power means to both rotatable members to enable continuous rotation thereof; and

carrier character stepping and carrier return drive mechanism comprising said second rotatable member on the carrier, control cables secured to said 20' frame structure and cooperating with said second rotatable member, dual stop racks cooperating in releasable engagement with the carrier and coordinated control components for said racks and said cables to accomplish high speed carrier character spacing movements and carrier return movements, by shifting said racks relative to said carrier and simultaneously selectively conditioning one of said cables to provide movement of said second rotatable member and the carrier along conditioned cable.

4. A power driven typewriter or the like comprising:

a frame support structure,

a carrier with print mechanism thereon,

means mounting said carrier on said support structure for lateral movement to enable said carrier to accomplish character spacing steps and a return to a start of line position,

a rotating capstan wheel journalled on said carrier with its axis normal to the lateral direction of movement of said carrier,

power means secured to said frame structure connected to continually rotate said capstan wheel,

at least two cables, one of which is a carrier space stepping cable and the other of which is a carrier return cable,

means fixing the ends of both of said cables to said frame structure with individual ones of said two cables being looped around said capstan wheel in opposite directions,

independent means connected to each cable to enable selective alternative tightening of each cable loop on said capstan wheel to thereby create a relative drive force between the selectively tightened cable and said carrier in one or the other direction,

an abutment means secured to said frame structure having a plurality of abutments each of which is adapted to singly, engagingly cooperate with said carrier to denote character spacing positions of said carrier.

control means for releasing engagement between said carrier and an engaged abutment and permitting engagement of the next successive abutment by. said carrier and simultaneously enabling momentary, selective tightening of said space stepping cable by the associated said independent means,

means for removing and maintaining all abutments away from a position where they can be engaged by said carrier and simultaneously enabling tightening of the carrier return cable by its associated independent means and subsequently maintaining tightness of said carrier return cable, and

means automatically rendered operative upon said carrier reaching the start-of-line position to release maintenance of tightness of said carrier return cable.

5. A power driven typewriter or the like machine 55 comprising:

a carrier shiftable along a path paralleling the typed line pattern;

a continually rotating type pallet wheel mounted on said carrier, said wheel having a plurality of independently operable type pallets each of'which has an associated and independently selectively actuatable pallet operating assembly, said type pallets being disposed on said type pallet wheel to rotate therewith in a planar path parallel to the typed line pattern;

powered means on and shiftable with said carrier connecting to and for continually rotating said type pallet wheel and providing a source of power for driving said carrier in character spacing steps in one direction and carrier return movement in the opposite direction; and

operating means, portions of which are adapted to engage with said type pallet wheel and said powered means enabling selection and printing operation of a desired type pallet and selective utilization of said 21 powered means for shifting of said carrier in a desired direction.

6. A power driven typewriter as defined in claim 5, wherein said powered means includes a uni-directionally rotating capstan wheel which serves as a common component to power the spacing action and the return action of said carrier.

7. A power driven typewriter or the like machine comprising:

a frame structure;

a platen on said frame structure for providing backing for a record medium;

a carrier mounted on said structure and shiftable back and forth in front of said platen between start-ofline and end-of-line positions; means connected to said carrier to shift said carrier;

print mechanism mounted on said carrier;

power means on said structure including a rotatable element on and shiftable with said carrier connected to at least a portion of said means to shift said carrier and to at least a portion of said print mechanism providing a power source for printing and carrier shifting movement; and

machine operating means including means enabling character spacing, back spacing and return movements of said carrier, and means for selecting and enabling printing of selected symbols by said print mechanism.

8. A power driven typewriter or the like machine as defined in claim 7, wherein said means enabling character spacing, back spacing and return movements of said carrier, comprises:

a movable escapement stepping device adapted to engage said carrier;

escapement control means connected to said escapement stepping device selectively enabling successive stepping actions and a complete disabling of said escapement;

a carrier stepping means with a stepping operator secured on said frame structure and providing a controllable clutching engagement with said rotatable element;

a carrier return means with a return operator secured on said frame structure and providing a controllable clutching engagement with said rotatable element;

control means for said stepping operator;

control means for said return operator; and

coordinating means between said stepping control means, said return control means and said escapement control means enabling a coincident operation of said escapement means and said stepping means for carrier stepping; and coincident operation of said escapement means and said return means for carrier backspacing and carrier return movement dependent upon the function desired.

9. A power driven typewriter or the like machine as defined in claim 8, wherein said machine operating means includes means connected to impart activating signals to said stepping and escapement coordinating means for enabling carrier spacing, backspacing and return functions including additional means automatically responsive to actuation of said type symbol selecting means to enable a character spacing function of said carrier during an action of said print mechanism when printing is not occurring.

10. A power driven typewriter or the like machine comprising:

a frame structure;

a platen on said structure for providing backing for a record medium;

a carrier mounted on said structure and shiftable back and forth in front of said platen between start-of-line and end-of-line positions;

print mechanism mounted on said carrier;

power means on 'said structure including a rotatable 22 element on and shiftable with said carrier providing a power source for printing and carrier shifting movement; means enabling character spacing, back spacing and carrier return movements, comprising:

(1) a movable escapement stepping device adapted to engage said carrier;

(2) escapement control means connected to said escapement stepping device selectively alternatively enabling successive stepping actions and a complete disabling of said escapement;

(3) a carrier stepping means with a stepping operator, both of which are secured on said frame structure, providing a controllable clutching engagement with said rotatable element;

(4) a carrier return means with a return operator secured on said frame structure and providing a controllable clutching engagement with said rotatable element;

(5) control means for said stepping operator;

(6) control means for said return operator; and

(7) coordinating means between said stepping control means, said return control means and said escapement control means enabling a coincident operation of said escapement means and said stepping means for carrier stepping, and enabling coincident operation of said escapement means and said return means for carrier.

backspacing and carrier return movement dependent upon the function desired;

said print mechanism comprising:

(1) a continually rotatabletype wheel connected to and rotatable by said rotatable element;

(2) a plurality of sets of independently operable type pallets, type pallet operators and operator latches pivotally mounted on said wheel in spaced apart circumferential disposition around the axis of said wheel;

(3) an electro-magnet with a high speed armature operated selecting lever comprising a type selector mounted on said carrier adjacent the rotary path of said latches; and

(4) a type operator roller abutment mounted on said carrier adjacent the rotary path of said type pallet operators; and

machine operating means including:

(1) means coordinated with the rotational position of said type wheel for actuating said electro-magnet type selector to cause its selecting lever to engage any desired one of said pallet operator latches to release and enable a rocking of its associated pallet operator, whereby continued rotation of said wheel will cause said rocked pallet operator to tangentially engage said roller abutment and transfer the tangential abutment force to a radial printing force on the associated type pallet causing the type pallet to undergo a printing stroke against the record medium and platen resulting :in a rebound of said type pallet and operator to a position where said latch is again effective to latch the associated type pallet and pallet operator in retracted position as the wheelcontinues rotation; and v (2) means to impart activating signals to said coordinating means for enabling carrier spacing, backspacing and return functions and including means automatically responsive to actuation of said type selector to enable a character spacing function of said carrier during an angular movement of rotation of said wheel when printing is not occurring.

11. For use in combination with a power driven typewriter or the like machine, a traveling carriage and carriage shifting mechanism comprising:

a frame structure;

a carriage shiftably mounted on said structure for shift ing movement back and forth along a fixed path between a start-of-line and an end-of-line position;

powered means on said structure including a rotatable element on and shiftable with said carriage providing a power source shiftable along with said carriage for furnishing power to accomplish carriage shifting movement;

means enabling character spacing, back spacing and return movements of said carriage, comprising:

(1) A movable escapement stepping device secured to said frame structure and adapted to engage said carriage;

(2) escapement control means connected to said escapement stepping device selectively enabling successive stepping actions and a complete disabling of said escapement;

(3) a carriage stepping means with a stepping operator secured on said frame structure and providing a controllable clutching engagement with said rotatable element;

(4) a carriage return means with a return operator secured on said frame structure and providing a controllable clutching engagement with said rotatable element;

(5) control means for said stepping operator;

(6) control means for said return operator; and

(7) coordinating means between said stepping control means, said return control means and said escapement control means enabling a coincident operation of said escapement means and said stepping means for carrier stepping; and coincident operation of said escapement means and said return means for carrier backspacing and carrier return movement dependent upon the function desired.

12. Carriage means in combination with a power driven typewriter or the like machine with frame structure comprising:

a carriage; print means mounted on said carriage means to mount said carriage on said frame structure for shifting movement of said carriage enabling character spacing and return to start-of-line position;

continuously rotating means mounted on said carriage;

said print means being connected to said continuously rotating means and deriving its actuating power therefrom; and

selectively operable control means having a portion in engagement with said continuously rotating means for deriving carriage operating power from said continuously rotating means and enabling character spacing and return to start-of-line movements of said continuously rotating means and said carriage.

13. A power driven typewriter or the like machine having print mechanism comprising:

a type pallet wheel assembly including a plurality of type pallets, each pallet having associated therewith a linkage assembly comprising independently operable pallet engaging hammer means and hammer latch means;

each said latch means being shiftable between latched and unlatched positions coacting with its associated said hammer means to normally latch said hammer means in a retract position and enabling cocking of said hammer means upon a selected shifting and unlatching of said latch means;

' means enabling selection and unlatching actuation of any one of said latch means at a fixed location in the rotational path of said type pallet wheel assembly during rotation of said wheel assembly;

means adapted to be engaged by an unlatched cocked hammer means at a second fixed location distinct from said first fixed location in said rotational path during rotation of said wheel assembly to cause a 24 reaction rebound movement of said hammer means approximate said second fixed location;

means cooperating between said hammer means and its associated type pallet means enabling a force 5 transfer between said rebounding hammer means and said type pallet means to result in a printing movement of said type pallet means;

means cooperating between said impacted hammer means and its associated said latch means enabling relatching of said impacted hammer means and its associated type pallet means in a retract position; and

means connected to and providing continual rotation of said type pallet wheel during selection and printing.

14. A power driven typewriter or the like machine comprising:

a continuously rotating type pallet wheel assembly including:

(1) a plurality of counterweighted pivoted type pallet levers with print faces on one end carried around the wheel, said levers being balanced so that centrifugal force of rotation urges said print faces in a radially inward direction relative to the axis of wheel rotation,

(2) coacting latching and operating linkage for each pallet lever comprising a portion of each pallet lever, an intermediate pivoted link and a tripping latch link,

(3) each type pallet lever including a heavy abutment arm serving as a counterbalance to shift radially outwardly relative to the wheel axis to a cocked position upon selection and release of said tripping latch link,

(4) said intermediate pivoted link including a combination abutment-hammer arm acting as a counterweight shiftable radially outwardly relative to the wheel assembly axis upon selected release of the associated said tripping link;

an abutment secured adjacent said wheel assembly and fixed against rotation about the axis of said wheel assembly and disposed in the path of rotation of an outwardly shifted portion of said abutment-hammer arm;

said intermediate linkage when selected and outwardly shifted being adapted, upon impact with said fixed abutment, to react with a rebound movement to a latched position, at the same time transferring force to said heavy abutment arm on its associated type pallet lever to thereby cause a radially outwardly directed printing stroke of the type face end of said pallet lever,

a platen located adjacent said type pallet wheel adapted to receive the force of a type pallet lever print stroke and cause a rapid reaction rebound of said pallet lever,

said tripping latch link being counterbalanced to move under centrifugal force to a latching position and to thereby engage and retain the associated intermediate lever in latched position, and

6 selecting means to engage and unlatch any specific tripping latch link during wheel rotation and prior to the type pallet lever associated with said tripping latch link reaching said fixed abutment print position.

15. A power driven typewriter or the like machine as defined in claim 14, wherein a track cam, non-rotatably secured in said typewriter adjacent the path of rotation of said tripping latch links, is adapted to be engaged by any selected latch link immediately subsequent to a printing movement of its associated pallet to positively shift said latch link back to a latching position.

16. A power driven typewriter or the like machine comprising:

power means,

a rotatable type pallet wheel connected to and continually rotated by power means,

independent linkage sets of (1) pallet levers, each With a type face symbol on one end,

(2) pallet lever operating elements, having operative and inoperative positions, and

(3) an element control and latch means adapted,

when selected, to unlatch and enable an associated operating element to be conditioned for subsequent operative movement,

all said sets being mounted on and rotating with said wheel, each set corresponding to a data indicative symbol to be recorded;

means to select and engage any desired one of said element control and latch means while said wheel is rotating, to thereby enable its associated operating element to accomplish a recording function during a succeeding increment of Wheel rotation; and

means adapted to be engaged by an enabled operating element during its rotation with said type pallet Wheel to cause said enabled operating element to impart an operative print force to its associated pallet lever, in a direction transverse to the rotational path of movement of said pallet levers.

17. A power driven typewriter or the like machine including a type pallet wheel assembly comprising:

a rotatable body with a plurality of coaxial annular combs, coextensive slots in adjacent combs constituting a plurality of sets of comb slots;

means securing said combs together as a unit;

a fixed abutment adjacent said rotatable body;

a set of a type character pallet lever, a hammer lever and a latching lever disposed in each set of comb slots, all of said levers in each set coacting and being retained, in a non-printing, retracted and latched position against centrifugal force acting on said levers, by said latching lever and being shiftable by centrifugal force resulting from operative wheel rotation to a cocked position upon selected unlatching movement of said latching lever and being adapted to receive an operating force from said fixed abutment being engaged by a rotating said hammer lever when said hammer lever is in cocked position to impart an operating force to and through said hammer lever to said pallet lever causing a rapid print stroke of said pallet lever and subsequent return of all levers in a said set to the latched position.

18. A high speed power driven typewriter or the like machine comprising:

a rotating typewheel assembly comprising: a rotatable body means, a plurality of type character pallet levers, means pivotally mounting said levers on and spaced around the periphery of said body, a plurality of type lever operating linkage assemblies equal in number to said pallets, individually associated with respective ones of said pallets and secured in spaced relationship around the periphery of said rotatable body means,

a cocking means non-rotatably mounted relative to and adjacent to the rotatable path of said typewheel assembly;

selectively operable means to momentarily shift said cocking means into the rotary path of movement said linkage assemblies at a selected time to impart a cocking impact to a selected operating linkage assembly,

means operative during a subsequent period of rotation of said typewheel for imparting a momentary impact force to said cocked operating linkage assembly urging the associated type lever character against a data receiving means to thereby print a selected character on the data receiving means, and

means operative immediately'subsequent to the type lever actuation to engage, reset and latch said impact operated type lever operating linkage assembly and associated type character pallet lever to an inoperative latched condition.

19. A high speed typewriter or the like machine as defined in claim 13, further comprising:

a carriage mounting said typewheel assembly and all of said means;

platen means for carrying a record data receiving medium adjacent said typewheel assembly; and

means providing stepped character spacing movement between said carriage and said record data receiving medium.

20. A power driven typewriter or the like machine utilizing a continuously rotating type pallet wheel, a support means for said wheel and a type pallet operating abutment means located on said support means adjacent and non-rotatable about the axis of said wheel, said wheel comprising:

a rotatable body,

a plurality of type symbol carrying pallet levers angularly spaced apart around the axis of said body and pivotably mounted on an annular axis coaxial with the axis of said body,

each pallet lever having associated therewith, independent control and operating linkage, each linkage capable of being enabled upon selection to subsequently impact said abutment means and provide a transfer of reaction force to its associated pallet lever to cause a print movement of said pallet lever, said print movement being supplemental and transverse to movement in a rotational path due to rotation of said rotatable body; I

means operable subsequent to a print movement of a said pallet lever for resetting said pallet lever and associated control and operating linkage to an inoperative non-selected position; and

means to select and enable any desired one of said control and operating linkages for subsequent operation by rotation into engagement with said abutment to develop and transfer a force to accomplish print action during continued rotational movement of said body.

21. A power driven typewriter or the like machine as defined in claim 20 wherein said operating abutment means comprises a roller, means mounting said roller on said support means including means journalling said roller on an axis parallel and eccentric to the axis of said wheel and means enabling minute adjustments of said eccentricity.

22. For use in a power typewriter, the subassembly of a rotatable type pallet Wheel, comprising:

a body,

a plurality of type pallet levers pivoted on a continuous annular axis coaxial to the axis of said body,

a plurality of independent sets of control and operating linkages mounted in said body coaxial to the axis of said body, one set for each type pallet lever, in alignment with and kinematically paired with the associated type pallet lever, and each said set of linkages including releasable latching means and separate force transfer means pivotally mounted and normally latched by said latching means but shiftab'le under centrifugal force when unlatched to a position capable of receiving a tangentially directed operating force and transferring such force as a pure radial force into the associated said pallet lever for accomplishing a printing stroke.

23. The combination defined in claim 22, wherein each said pallet lever has a type character secured on one end, a fiat arm extending from said one end to said pallet lever pivot location, and said arm has its shank constructed with its thin dimension in cross section in the direction of wheel rotation to thereby provide an inherent resilience in said type pallet lever enabling flexing in the direction of rotation of said wheel so that the pivoted portion of a type lever can continue its rotational move- 27 ment while the type character is momentarily impacted and has its rotary movement stopped during printing.

24. A continuously rotating type wheel, for use in combination with a power driven typewriter, comprising:

a wheel hub providing a plurality of coaxial annular combs;

a plurality of individually selectable type pallets individually pivotally secured in one of said annular combs capable of individual printing movement supplemental to and during rotational wheel movement so as to enable selected type pallet levers to be moved through a supplemental printing stroke and back to a latched position so rapidly during wheel rotation that a high quality character is printed on the record medium;

a plurality of means, equal in number to said plurality of pallets, on said wheel hub and individually pivotally secured in other of said annular combs enabling selection and conditioning of the desired type pallet for subsequent printing; and

each of said last named plurality of means including means operable subsequent to selection and conditioning of a selected type pallet to engage and rapidly move the conditioned type pallet through the print stroke.

25. For a power driven typewriter, a type pallet wheel assembly including a plurality of type pallets, each with an associated assembly comprising independently operable hammer means and hammer latch means; each said latch means coacting with its associated said hammer means to enable cocking of said hammer means upon selection and unlatching of said latch means; means on each hammer means enabled by cooking of said hammer means to engage an auxiliary device during rotation of the wheel to cause a reaction rebound movement of said hammer means; means cooperating between each said hammer means and its associated type pallet means enabling a force transfer between a said hammer means subject to rebound force and said type pallet means to result in a printing movement of said type pallet means; and means cooperating between each said hammer means and its associated said latch means enabling latching of a said impacted hammer means and its associated type pallet means in a retract position.

' 26. For use in combination with a power driven typewriter, a type wheel comprising:

a type wheel hub;

a plurality of weighted type pallet levers pivotally mounted in a circumferentially spaced relation on said type wheel hub for movement to printing and non-printing position; and

a plurality of operator means, equal in number to said plurality of pal-let levers, pivotally mounted on said typewheel hub, each of said operator means being structurally separate from and associated with a single one of said pallet levers and capable of undergoing a shifting movement accompanied by a force transfer to an associated pallet lever enabling associated pallet levers to be actuated toward their printing position by pivotal shifting of said operator means resulting from rotary movement of said operator means past and engagement of said operator means with an auxiliary device.

27. For use in a power driven typewriter or the like, a rotatable type pallet wheel comprising: a plurality of independent sets of a pivotally mounted pallet lever with a desired type face symbol on one end; a pivotally mounted pallet lever operating element, having operative and inoperative positions; and a pivotally mounted element control and latch means adapted, when selected, to unlatch and enable an associated operating element to be conditioned for subsequent operative movement; all said sets being mounted on and rotatable with said wheel, each set corresponding to a data indicative symbol to be recorded.

28. For use in a power driven typewriter or the like, a rotatable type pallet wheel assembly comprising:

a wheel hub;

a plurality of counterweighted type pallet levers with print faces mounted on and carried by said wheel hub, said levers being balanced so that centrifugal force of rotation will urge said print faces in a radially inward direction relative to the axis of wheel hub rotation;

coacting latching and operating linkage for each pallet lever consisting of a portion of each pallet lever, an intermediate pivoted link and a tripping latch link;

each type pallet lever including a heavy abutment arm serving as a counterbalance to shift radially outwardly relative to the Wheel hub axis to a cocked position upon selection and release of said tripping latch link;

said intermediate pivoted link including a combination abutment-hammer arm acting as a counterweight shiftable radially outwardly relative to the wheel assembly axis upon selected release of the associated said tripping link;

said intermediate linkage being adapted, when subjected to an external operating force, to react with a rebound movement to a latched position, at the same time transferring force to said heavy abutment arm on its associated type pallet lever to thereby cause a radially outwardly directed printing stroke of the type face end of said pallet lever, and

said tripping latch link being counterbalanced to move under centrifugal force to a latching position and to thereby engage and retain the associated intermediate lever in latched position.

29. A hub structure for pivotally carrying type pallet levers and pallet lever operating links of a type pallet wheel having a plurality of axially spaced coaxial groups of type pallet levers and pallet lever operating links comprising: a plurality of coaxial axially abutted radially slotted ring members; means securing said ring members together; and at least two coaxial locking ring means enclosed between adjacent ones of said ring members, each ring means intersecting slots in said ring members, whereby at least two coaxial groups of pivot journals con stituted by portions of said ring means are provided, each group of which is to pivotally carry a respective one of the coaxial groups of type pallet levers and pallet lever operating links.

30. A power driven typewriter or the like machine comprising: a frame support structure; a print mechanism carrier; means mounting said carrier on said support structure for shifting movement of said carrier enabling character spacing of said carrier and return of said carrier to start-of-line position; continually rotating means including a capstan wheel rotatably journalled on said carrier; power means connected to continually rotate said capstan wheel, and selectively operable control means, secured to said structure for enabling character spacing and return to start-of-line movements of said carrier, comprising: at least two cables, one of which is a carrier space stepping cable and the other of which is a carrier return cable, means including a resiliently biased anchor device fixing the ends of said cables to said frame support structure with both of said two cables being looped around said capstan wheel; and at least two independent means, individual ones of which are connected to and operable on an associated one of each of said cables to enable selective tightening of each cable loop on said rotating capstan wheel to thereby create a drive force by said capstan wheel along said cables in one or the other direction for character spacing steps and return to start-of-line position by said carrier.

31. A power driven typewriter or the like combination as defined in claim 35, wherein said control means further comprises: 

1. A POWER DRIVEN TYPERWRITER OR THE LIKE MACHINE COMPRISING: A FRAME STRUCTURE; A PLATEN ON SAID STRUCTURE FOR PROVIDING BACKING FOR A RECORD MEDIUM; A CARRIER MOUNTED ON SAID STRUCTURE AND SHIFTABLE BACK AND FORTH IN FRONT OF SAID PLATEN BETWEEN START-OFINE AND END-OF-LINE POSITIONS; MEANS CONNECTED TO SAID CARRIER TO SHIFT SAID CARRIER; PRINT MECHANISM MOUNTED ON SAID CARRIER; AND 